Five men have been jailed for between 20 months and 12 years in the UK's "largest ever prosecution for cannabis supply", police said.

The gang smuggled 20 tonnes of cannabis, worth £80m, from the Netherlands to the UK and stored it under piles of frozen meat in cold stores.

Their audacious operation was uncovered in December 2011 when police seized 50kg of cannabis, worth £420,000, from a vehicle on the M67 and raided an address in Oldham, Greater Manchester, linked to the gang.

In the police investigation that followed, dubbed Operation Bizarre, officers discovered a commercial premises in Mottram, Greater Manchester, from where the cannabis was supplied.

The trail led them to a cold storage company in County Durham where a 1.8 tonne shipment of cannabis, valued at more than £7m was discovered at the a cold store hidden under frozen meat.

Further investigations by West Yorkshire police led officers to identify 13 previous shipments which could have contained as much as 20 tonnes of cannabis with an estimated street value of more than £80m.

Four of the men denied the charges but were convicted at a crown court trial in Manchester. A fifth pleaded guilty.

Michael Levy, 44, of Manchester, was sentenced to eight years' jail and four years imprisonment for two counts of conspiracy to supply a Class B drugs, to be served concurrently.

Ian Thompson, 42, of Manchester, was sentenced to five years in jail for one count of conspiracy to supply a Class B drug. Carmello Anthony Abela, 53, of Tameside, was sentenced to 12 years jail and six years imprisonment for two counts of conspiracy to supply a Class B drug, to be served concurrently. His brother Geno Abela, 42, of Manchester, was sentenced to nine years jail and five years imprisonment for two counts of conspiracy to supply a Class B drug, to be served concurrently.

Rizwan Safdar, 30, of Oldham, had previously pleaded guilty to conspiracy to supply a Class B drug and was jailed for 20 months.

Four men from Bradford and a man from Milton Keynes have already been sentenced for their part in the large-scale cannabis ring.

Police said the convictions came after a two-year investigation which involved DNA analysis and painstaking work to create an "overwhelming amount of evidence against the defendants".

The Abela brothers were linked to a fake transport company used to transport the cannabis.

The pair used the cash they made to pay for properties in Malta, houses in Greater Manchester, expensive executive cars and a catering business.

Police now hope to claw some of this money back and have identified financial assets of the defendants which they want to strip from them under the Proceeds of Crime Act.

Temporary Detective Inspector Phil Little, of West Yorkshire's crime division, said: "This was a long and complex investigation with officers conducting inquiries throughout the UK and Holland in order to gather the evidence necessary to show the full extent of the defendants' criminality.

"These men were involved in the distribution and supply of millions of pounds worth of cannabis and the action taken has made sure that a significant amount of the Class B drug will not be sold on the streets of north England.

"The judge said this was the largest ever prosecution for cannabis supply in the UK.

"We will actively pursue those involved in the supply of illegal drugs and work across borders with other forces to ensure offenders are brought to justice.

"We would like to thank our colleagues in Greater Manchester police for their assistance in this operation and the successful convictions that have resulted.

"In addition to the lengthy custodial sentences which these individuals now face, we are also making sure their crimes will not pay by stripping them of the profits and assets of their offending under the Proceeds of Crime Act."